1. Field of the Invention
The present invention is related to mounting devices for printed circuit boards and other objects sensitive to shock and vibration. More particularly, the present invention relates to a mounting device which provides resilient suspension for isolating shock and vibration, and which further provides frictional dampening for dissipating the energy associated with the shock and vibration.
2. Description of the Prior Art
With an increasing number of articles being equipped with electronic circuitry in the form of printed circuit boards, the need has commensurately increased to ensure that the related constituents thereof, the electronic components, the electrical interconnections and the substrate on which the electrical interconnections are printed, are each adequately protected from vibration and shock damage.
Typically, printed circuit boards are mechanically secured to a chassis of an article without provision for resilient mounting. As a result, in the event that shock or vibration is delivered to the article from an external source, the printed circuit board may be damaged by direct transmission thereto of the shock or vibration from the chassis.
Mounting a printed circuit board by use of a simple spring-biased suspension between it and the chassis of the article will not entirely solve the problem of protecting the printed circuit board from potential damage from shock and vibration. A major reason for this involves unstable mechanical support coupled with undesirable persistence of suspension vibration. Shock or vibration delivered by an external source to the chassis of the article will be transmitted to the spring-biased suspension resulting in suspension vibration of a particular frequency and amplitude that in time will strain the substrate of the printed circuit board, leading to its eventual failure. Another reason that a simple spring-biased mounting for a printed circuit board is not desirable is that suspension vibration will in time cause failure of the electrical leads connecting to the printed circuit board from elsewhere in the article.
Accordingly, what is needed in the art is a mounting device which provides for a mechanically stable yet yieldable suspension for printed circuit boards, and other vibration and shock sensitive objects, with respect to an article, and which also provides for dissipation of the energy of the shock and/or vibration so that suspension vibration is rapidly dampened.